The invention concerns a material on an aluminum basis for anti-friction bearings, comprising an aluminum alloy with 10-25 wt % tin or 5-25 wt % lead and impurity-caused components.
The aluminum alloy, known under the abbreviated designation of AlSn20, usually contains impurities of iron, which are usually indicated as less than 0.7% by the manufacturer. In fact, the impurity-caused iron content, however, usually is in the range of 0.3-0.4 wt %. According to current assessments, iron in aluminum alloys is anything but desired, since intermetallic phases, such as Al3Fe or in the presence of silicon, FeSiAl5, which are formed, have an embrittlement effect and thus reduce resistance to fatigue and have a negative effect with regard to shaping capacity. Iron aluminide crystallizes, namely, producing beam-like and needle shapes, or forms thin plates, which form potential breakage nuclei and hinder shaping. The effort, therefore, is to keep the iron content of the aluminum alloy forming anti-friction bearings as low as possible, which limits the use of secondary aluminum or circulating scrap for the production of the anti-friction bearing material and raises production costs.
Typical materials on an aluminum basis for anti-friction bearings are also known from DE-A 69936 and from U.S. Pat. No. 4,471,032. From these publications, alloy additives are known to a large extent; the problem mentioned in the preceding, however, is not addressed. Proceeding from here, the goal of the invention under consideration is to improve a material for anti-friction bearings of the type described above, to the effect that it exhibits, on the one hand, a good shaping behavior and has a high resistance to fatigue, and furthermore, contains additives which form hard phases, but which do not exhibit an embrittlement effect, wherein the material for the anti-friction bearings can be produced at a low cost.